According to a new study, Southern California’s air quality now has 50% less carcinogenic pollutants, but that doesn’t mean it’s time for the Golden State to celebrate just yet.

Released on October 2, the South Coast Air Quality Management District’s new study reveals that the air quality of Southern California has improved significantly since the last time the air was checked in 2005, with less than half as many cancer-causing toxins in the air.

The news is not surprising to many Californians, as brown smog no longer blots out the mountains crisscrossing the West Coast area.

However, pockets of pollutants persist. Areas of the region still suffer from poor air quality, as toxins like diesel particulate matter and benzene continue to hang in the air.

The areas of most concern are the ports of Long Beach and Los Angeles, thanks to the vast fleet of trucks and oceanic shipping vessels that comes and goes every day. On the other hand, the areas with the lowest cancer risks are the Coachella Valley, southwest Riverside County, and south Orange County.

“Air pollution controls on everything from cars to trucks to industrial plants have dramatically reduced toxic emissions in our region,” said the South Coast Air Quality Management District’s executive officer Barry Wallerstein. “However, remaining risks are still unacceptably high in some areas. We need to maintain our commitment to reducing toxic emissions so that everyone can breathe healthful air.”